Electronically tunable SAW chemosensors

A new tunable SAW chemical sensor suitable for applications in sensor arrays is proposed and demonstrated experimentally. The sensor is based on a SAW delay line with a metallic waveguide on the surface of the piezoelectric substrate. An electrical voltage applied between this waveguide and two electrodes placed on the substrate surface next to the waveguide gives rise to local perturbations of the substrate properties in the vicinity of the waveguide, thus leading to a variation in the sensor selectivity for different chemical vapours. The device was used to sense several types of alcohol vapours; experimental results are presented